Suppose X is normally distributed with a mean of 75 and a standard deviation of 4. Compute P(70 < X < 80). 0.8944 0.7888 0.3944 0.1056 b- Suppose X is normally distributed with a mean of 15 and a standard deviation of 5. Find the 90th percentile for X. 19.5 19.1 21.4 20 c- Consider the following hypothesis test. The following results are for two independent samples taken from the two populations. Sample 1 Sample 2 What is the value of the test statistic? (round to 2 decimal places) 6.05 3.20 2.29 5.12
Added by Kenneth C.
Step 1
z1 = (70 - 75) / 4 = -1.25 z2 = (80 - 75) / 4 = 1.25 Now, we can look up the probabilities in the z-table or use a calculator to find the area under the curve between these z-scores. P(70 < X < 80) = P(-1.25 < Z < 1.25) = P(Z < 1.25) - P(Z < -1.25) = 0.8944 - Show more…
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